The OSO-7 Satellite

OSO-7, like the other Orbiting Solar
Observatory missions, was primarily a solar observatory designed to
point a battery of UV and X-ray telescopes at the Sun from a platform
mounted on a cylindrical wheel. The detectors for observing cosmic
X-ray sources were the X-ray proportional counters,
built by MIT, the hard X-ray telescope by UC San Diego and the Gamma Ray
Monitor by the University of New Hampshire.